Adjustable triangle.



NOQ 861,507. PATENTED JULY 30, 1907. H. 0. FIELD & c. MURK.

ADJUSTABLE TRIANGLE.

APPLICATION nun MAY 7, 190a.

ms NORRIS PETERS cm, wnsmuarou, o c

HAROLD O. FIELD AND OHRISTEN MORK, OF MOSCOW, IDAHO.

ADJUSTABLE TRIANGLE.

Specification of Letters Patent.

Patented July 30, 1907.

Application filed May '7, 1906. Serial No. 315,694.

To all whom it may concern:

Be it known that we, HAROLD O. FIELD and OHnis- TEN Monk, subjects of the King of Norway, residing at Moscow, in the county of Latah and State of Idaho, have invented a new and useful Adjustable Triangle, of which the following is a specification.

This invention relates to drafting instruments and more particularly to triangles.

The object of the invention is to provide a device of this character having one right angle and having a member movably connected thereto so as to form angles of different degrees.

With these and other objects in view the invention consists of certain novel features of construction and combinations of parts which will be hereinafter more fully described and pointed out in the claims.

In the accompanying drawing is shown a plan view of the best form of the invention now known to us.

Referring to the drawing by characters of reference, B is the base of the instrument the same being provided with an arm I extending from one end thereof so as to form a right angle Z. This arm has a reduced extension lc at its free end. The base B is gradually reduced in width toward that end thereof farthest removed from the arm I and as shown at c. A link D is pivotally connected to the reduced portion 0, and another longer link H is pivotally connected to the base B adjacent the center thereof as shown at f. A strip A is disposed adjacent the base B and has one end portion gradually reduced in width at b the length of this reduced portion being equal to the length of the reduced portion 0. Both of the reduced portions come to points a which are constantly in contact. A recess shown by dotted lines at j is formed in one end of the strip A to receive the extension is. A link O is pivoted to the reduced extension I) and to one end of the link D, said links O and D being of the same length and'iorming a toggle. Another longer link G is pivoted to the strip A as shown at e and is also pivoted to one end of the link H, both of the links G and H being of the same length and forming a toggle. Connecting strips E and F are pivoted as at d to the connected ends of the links O and D, and are also pivoted as at g and h to the links G and X. The parts are so proportioned that by pushing the connected ends of the links G and H toward the points a the strip A will be swung away from the base without, however, moving the two points at out of contact. When the movement of the links G and H is reversed the strip A will be swung toward the base with the points a still in contact and the extension 7c will finally become seated within the recess j to form a complete triangle. It will be seen that with this construction the angle between the parts A and B can be adjusted to any desired degree. An important feature of the invention is the disposition of the parts whereby the points a are maintained constantly in contact.

What is claimed is:

1. An instrument of the character described comprising a base, an adjustable strip, said strip and base having reduced portions terminating in points, and foldable connections pivotally connected to the base and strip for maintaining the points of said base and strip constantly in contact during the adjustment of the strip in relation to the base.

2. An instrument of the character described comprising a base having an arm extending at a right angle from one end thereof, a strip, said strip and base having gradually reduced portions terminating in points, link connections between the strip and base, and pivotal connections between the links, the points of said base and strip being maintained constantly in contact.

3. An instrument of the character described comprising a base, an adjustable strip, said base and strip having pointed ends constantly in contact, and toggle connections between the base and strip for adjusting the strip to desired angles in relation to the base.

4. An instrument of the character described comprising a base, an adjustable strip, said base and. strip having pointed ends constantly in contact, toggles connecting the base and strip for adjusting said strip to any desired angle in relation to the base, and link connections between the toggles.

5. An instrument of the character described comprising a base, an arm extending at a right angle from one end thereof,-said arm having an extension, an adjustable strip adapted to be engaged by the extension, said base and strip being tapered toward one end to form constantly contacting points, toggle connections between the base and strip, and links connecting the joint of one of the toggles with intermediate points of the links of the other toggle.

6. An instrument of the character described comprising a base, an arm extending at a right angle from one end thereof, said arm having an extension, an adjustable strip adapted to be engaged by the extension, said base and strip being tapered toward one end to form constantly contacting points, and toggle connections between the base and strip.

HAROLD o. FIELD. CHRISTEN Monk.

In presence of AXEL HAMSTEDT, G. F. WALKER. 

